AIS-CTRX Class B AIS Transponder Manual
VDM Message Format
!--VDM,x1,x2,x3,a,s--s,x*hh<CR><LF>
Where
• x1 = Total number of sentences needed to transfer the message , 1 to 9
• x2 = Sentence number, 1 to 9
• x3 = Sequential message identifier, 0 to 9
• a = AIS Channel, "A" or "B"
• s - - s = Encapsulated ITU-R M.1371 radio message
• x = Number of fill-bits , 0 to 5
VDM Message Types
For example, the information contained in the s - - s portion of the VDM = Encapsulated ITU-R M.1371
radio message. Note that messages 5 and 19 may be sent as multi part messages using the x1, x2
and x3 parameters for message sequence control
VDL Message Number VDM Message Description
AIS Target Display Information
1, 2, 3, 9,18, 21 position report
4 base station report
5 voyage related data
19 Class B – extended data
Safety message handling
12 addressed safety related
14 broadcast safety related
External Application handling
6 binary addressed
8 binary broadcast
System control
7 binary acknowledge (INFO)
10 UTC and data inquiry (INFO)
11 UTC and data response (INFO)
13 safety related ack (INFO)
15 interrogation (INFO)
16 assignment mode command (INFO)
17 DGNSS corrections (INFO)
20 data link management (INFO)
22 channel management (INFO)
Note that messages 5 and 19 may be sent as multi part messages.
1.1E 27 LD2103